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 Bubo vosseleri

This taxon is Not Recognised as a species by BirdLife International.

Taxonomic source(s)
Sibley, C. G.; Monroe, B. L. 1990. Distribution and taxonomy of birds of the world. Yale University Press, New Haven, USA.

Taxonomic note
Bubo poensis (del Hoyo and Collar 2014) was previously split as B. poensis and B. vosseleri following Sibley and Monroe (1990, 1993).

48 cm. Large, "eared" owl of forest. Heavily barred, richly-coloured upperparts. Pale underparts, heavily splotched on breast but finely barred on belly and flanks. Orange-brown eyes. Similar spp. Spotted Eagle-owl B. africanus is smaller, with white spotting on wing-coverts, white mantle-edging, and yellow eyes. Voice Series of low pop pop pop notes, rising and falling in crescendo and speed. Hints Forest and forest-edge. 

Distribution and population
Bubo vosseleri is distributed throughout the Eastern Arc Mountains of Tanzania, having been recorded from both the East and West Usambara Mountains (including Mt Nilo Forest Reserve (Cordeiro 1998; Seddon et al. 1999a), Uluguru North Forest Reserve (above Tegetero; Hunter et al. 1998), Mkungwe Forest Reserve (15 km north-east of the Ulugurus and particularly common; D. C. Moyer and E. A. Mulungu in litt. 1999), Iwonde Forest in Udzungwa Mountains National Park (T. Butynski in litt. 1999), Kilombero Nature Reserve (Mt Mufu) (Barnes et al. 1999), and Uzungwa Scarp Forest Reserve (along the Kihanga and Mpimbili rivers and in the Mbawi sector; D. C. Moyer and E. A. Mulungu in litt. 1999). There are also unconfirmed reports or probable records from three other locations (J. Fjeldså in litt. 1998; Moreau 1964; D. C. Moyer and E. A. Mulungu in litt. 1999; T. Romdal in litt. 1998). Records from lowland forest in the Usambaras during October-March (Evans 1997b; D. C. Moyer and E. A. Mulungu in litt. 1999) suggest that it may be resident there and the total population may thus be higher than the previous estimate of 200-1,000 individuals (Evans 1997b).

Most records are from montane and submontane evergreen forest (800-1,500 m), with some from lowland evergreen forest down to 200 m (Zimmerman et al. 1996). It is presumed to be a canopy-dwelling species (Zimmerman et al. 1996). It may be able to tolerate some human disturbance of forest structure, since it occurs on the forested borders of tea plantations (Zimmerman et al. 1996), and several young birds have been found in forest where the understorey has been cleared for cardamom cultivation. The diet appears to be exclusively small mammals (rodents, insectivores and possibly dwarf bushbabies Galagoides; T. Butynski in litt. 1999; D. C. Moyer and E. A. Mulungu in litt. 1999). The breeding season is thought to be November-February. The nest-site may be a tree-hole.

Unreserved forests in the East Usambaras are under heavy pressure from subsistence agriculture, pit-sawing and grazing livestock (Cordeiro 1998), although most forests in this region have been gazetted as protected areas since 1997-2004 (N. Burgess in litt. 2007). There is also pressure on forest reserves in many areas and this is likely to increase as stocks of fuelwood and timber outside reserved areas are depleted (Cordeiro 1998; Seddon et al. 1999a).

Conservation Actions Underway
CITES Appendix II. The East Usambara Catchment Forest Project is curbing forest destruction and incorporating much of the remaining unprotected forest into reserves, e.g. at Mt Nilo Forest Reserve (Cordeiro 1998). However, the lack of jurisdiction over neighbouring Public Lands Forest threatens the long-term prospects of reserves (Cordeiro 1998). Conservation action in the Ulugurus focuses on assisting local initiatives and increasing the involvement of local communities in forest management (Buckley and Matilya 1998). Iwonde Forest in Udzungwa National Park is well protected (T. Butynski in litt. 1999). Conservation Actions Proposed
Conduct surveys to establish population densities and sizes at known locations (D. C. Moyer and E. A. Mulungu in litt. 1999; Seddon et al. 1999a). Establish a programme to monitor its population and habitat on a regular basis (Seddon et al. 1999a). Improve the protection and management of reserves within the species's range. Continue to increase the involvement of local people in forest management.

Barnes, J.; Barnes, R.; Burston, P.; Githiru, M.; Leckie, J.; Mulwa, R.; Pilgrim, J. 1999. Project Kasigau '98.

Buckley, P.; Matilya, J. G. 1998. Saving Tanzania's mountain forests. World Birdwatch 20: 16-19.

Cordeiro, N. J. 1998. A preliminary survey of the montane avifauna of Mt Nilo, East Usambaras, Tanzania. Scopus 20: 1-18.

Evans, T. D. 1997. Records of birds from the forests of the East Usambara lowlands, Tanzania, August 1994 - February 1995. Scopus 19: 92-108.

Hunter, N.; Carter, C.; Mlungu, E. 1998. A new location for the Usambara Eagle Owl Bubo vosseleri. Scopus 20: 52-53.

Moreau, R. E. 1964. The re-discovery of an African owl Bubo vosseleri. Bulletin of the British Ornithologists' Club 84: 47-52.

Seddon, N.; Ekstrom, J. M. M.; Capper, D. R.; Isherwood, I. S.; Muna, R.; Pople, R. G.; Tarimo, E.; Timothy, J. 1999. Notes on the ecology and conservation status of key bird species in Nilo and Nguu North Forest Reserves, Tanzania. Bird Conservation International 9: 9-28.

Zimmerman, D. A.; Turner, D. A.; Pearson, D. J. 1996. Birds of Kenya and northern Tanzania. Helm, London.

Text account compilers
Ekstrom, J., Evans, M., Shutes, S., Starkey, M., Symes, A., Taylor, J.

Burgess, N., Butynski, T., Fjeldså, J., Moyer, D., Mulungu, E., Romdal, T.

Recommended citation
BirdLife International (2015) Species factsheet: Bubo vosseleri. Downloaded from on 05/07/2015. Recommended citation for factsheets for more than one species: BirdLife International (2015) IUCN Red List for birds. Downloaded from on 05/07/2015.

This information is based upon, and updates, the information published in BirdLife International (2000) Threatened birds of the world. Barcelona and Cambridge, UK: Lynx Edicions and BirdLife International, BirdLife International (2004) Threatened birds of the world 2004 CD-ROM and BirdLife International (2008) Threatened birds of the world 2008 CD-ROM. These sources provide the information for species accounts for the birds on the IUCN Red List.

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Additional resources for this species

ARKive species - Usambara eagle-owl (Bubo vosseleri) 0

Key facts
Current IUCN Red List category Not Recognised
Family Strigidae (Typical Owls)
Species name author Reichenow, 1908